Sound reproducing instrument



Nov. 24, 1931. TUR. MITCHELL. 1,833,789

SQUND REPRODUCING INS TRUMENT Filed April 5. 1929 azmzamzzzyzzzhzz,

INVENTOR Patented Nev. 24,- I

UNITED STATES" PATENT OFFICE" THEODORE R. 'OF WICHITA, IK.ANSAS scum) nnrnonnomeinsrnnmnm Application filed April 3, 1929. Serial No. 352,305.

I This invention relates to sound reproduction and vibration is reduced toa minimum and sound caused by the moving parts is 1 practically completely absorbed before reaching the turntable, with the result true tone reproduced by the record is provided.

A further object of the invention is to p vide a turntable for a sound reproducing inporting and driving the same that not only absorbs/all, extraneous sounds but is practically noiseless in its operation.

Another object ofxthe invention is. to pro- 7 vide a turntable ,drive that includes coil springs which function to drive the table after the latter is started.

A still furtherobject of the invention is to provide an improved turntable .as' well as a mounting and drive therefor, that together with themounting and drive is primarily 2 designed for a reproducing instrument for talking pictures and which enables the instrume'nt to provide .clear and true reproductions. 1 5

- A further object of the invention is to pro- 3 vide a-device of the character set forth for reproducing instruments. that is extremely simple'in construction, inexpensive to manufacture, easy to install, and eflicient in operation 7 v and service. i 1 v This invention. also conslsts in certa n 1 other features of construction and in the combination and arrangement of the several parts. to be hereinafter fully described. illus- 40 t-rated in the accompanying specifically pointed out in-jthe' appended rawings and claimsr In describing my invention in detail, reference will be had to the accompanying drawings wherein like characters denote like. or corresponding parts throughout the several views, and in which: i v

Figure 1 is a' sectional view taken through my improved turntable and illustrating the mounting and drive means therefor.

reference numeral? includes a relatively thin tnrnatable as will be apparent with the re- -Referring to the drawings in detail, the

reference numeral l'indicates a motor or other driving means which is supported in the usual manner and includes a drive shaft 2.

Secured to the drive shaft intermediate its 00 jends and through the instrumentality of a strument, that is of a .weight toact in the nature of a fly wheel and has means for'sup-- pin 3 is a collar i which has extending fromdiametrically opposite sides tliereof arms 5, and these arms have formed with their outer ends substantially 'U-sha-pe members 6 that rise therefrom as best shown in Figure 1 so as to disposethe arms of the U-shape mem-' bers 6' in a position for a purpose which will be presently set-forth. v

The turntable which is indicated by the top but has a relatively thick flange 8' de- I pending from the periphery thereof and which adds materially to the weight of the sult the'turntable is in wheel.

the nature of' a'fly Dependingcentrally from thev bottom vof the top of the turntable is a hub -9 and extending between the hub-9 and the flange 8 are so reinforcing fins 10. Two opposedfins 10 are v enlarged for a portion of their length at their connection with the hub 9Tfor the purpose of providing extensionslland these extensions .11 are arranged in the path of '85 the arms of the U-shape members as best a shown in Figure 1.

The last mentioned fins are provided with openings adjacent their outer ends for the purpose of receiving one of .the ends of coil springs 12, while the opposite ends of said coil springs 12 are secured in openings formed in the arms 5 adjacent their outer ends.

The hub 9 is, provided with a bore to accommodate 'the'drive. shaft 2, and disposed between the outer end of the drive shaft 2 and the inner end of the bore isa ball 13 which ofcourse acts as an anti-friction hearing. Rising from the center of the top of the turntable is a stud pin 14 which'is adapted l to be passed through the central opening of a record A as shown, and the top of the turntable has secured thereto in the usual manner a disk B of felt for supporting the record as will be apparent. I have also shown what is termed an electrical pick-upC which of course forms no part of the present invention but is used in reproducing instruments for talking picture s.

From the above description and disclosure of the drawings, it will be obvious that I have provided a device that not only efficiently drives the turntable of a reproduclng instrument, but will reduce friction and vibration to a minimum as well as absorb extraneous sounds and sounds for moving parts of the instrument before they reach the turntable which as shown is of a weight to act in the nature of a fly wheel, therefore it cooperates with the other elements of my device to enable a reproducing instrument to reproduce true and clear tones.

In the operation of my device, the motor 1 is started in the usual manner, such movement causes the drive shaft 2 thereof to rotate the arms 5 together with their U-shape members, an one of the arms of each U- shape member will engage its extension 11 and thereby start the turntable which after it has gained considerable momentum will free the extensions 11 from the arms of the U- shape members, with the result the drive thereafter will be through the instrumentality of the coil springs 12 and the extensions 11 will be disposed substantially midway between the arms of the U-shape members-as shown in Figure 2 of the drawings.

It is thought from the foregoing description that the advant ges and novel features of my invention will e readily apparent.

I desire it to be understoodthat I may make changes in the construction and in the combination and arrangement of the several parts, provided that such changes fall within the scope of the appended claims.

What I claim is:

1. In a reproducing instrument, a record table, a record stud 'oin rising from the top of the record table, a hub depending centrally from the top and including a bore to looselv receive a drive shaft. a ball arranged in the bore between the drive shaft and inner end of the bore, and means for driving said record table from said shaft.

2. In a reproducing instrument, a turntable, a relatively thick flange depending from the periphery of the top of said-turn table, a hub depending centrally from the top, reinforcing fins between the flange and hub, extensionsformed with two opposed fins, means engageable with the extensions to initially move the turntable and resilient means between the initial moving means and thfllast mentioned fins for driving the turns ta e.

:fins respectively for the purpose specified.

In testimony whereof I afiix my signature.

THEODORE R. MITCHELL. 

